<h2>选择题</h2>
<ul class="chooseUl">
    <li>
        <h3>{{item.question}}</h3>
        <nz-radio-group style="padding-left:12px;width:100%;" [ngModel]="userExam.answer1" (ngModelChange)="customChange($event)">
            <div class="radioDiv">
                <label nz-radio [nzValue]="'A'">
                    <span>{{item.optionA}}</span>
                </label>
                <label nz-radio [nzValue]="'B'">
                    <span>{{item.optionB}}</span>
                </label>
                <label nz-radio [nzValue]="'C'">
                    <span>{{item.optionC}}</span>
                </label>
                <label nz-radio [nzValue]="'D'">
                    <span>{{item.optionD}}</span>
                </label>
            </div>
        </nz-radio-group>
    </li>
</ul>